Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Humboldt-universitaet Zu Berlin

Forschungszentrum Rossendorf E.v.

Quantiox Gmbh

Humboldt-universtaet Zu Berlin

Humboldt-universität Zu Berlin

Mykhaylo Semtsiv

William Ted Masselink

Roman J Dietz

Björn Globisch

Thorsten Göbel

Roman Dietz

Manfred Helm

Nikolai Georgiev

W Ted Masselink

Thomas Dekorsy

Mathias Ziegler

Sebastian Dressler

Sebastian Dreßler

A photoconductor for emitting and/or receiving electromagnetic waves is provided. The photoconductor comprises a material region comprising a first and a second section, wherein the second section provides a higher density of charge carrier trapping centers and/or recombination centers than the first section, and a confinement generating a sub-band structure of the charge carrier energy states in the material region. The first and the second section are arranged and configured in such a manner that a maximum of the carrier probability density of the sub-band ground state is located in one of these sections and a maximum of the carrier probability density of an excited sub-band state is located in the respective other section.

Photoconductor for emitting and/or receiving electromagnetic waves

A terahertz antenna includes at least one photoconductive layer which generates charge carriers upon irradiation of light and two electroconductive antenna elements via which an electric field can be applied to at least one section of the photoconductive layer. The photoconductive layer being doped with a dopant in a concentration of at least 1&#xd7;1018 cm&#x2212;3, the dopant being a transition metal. The photoconductive layer is produced by molecular beam epitaxy at a growth temperature of at least 200&#xb0; C. and not more than 500&#xb0; C., the dopant being arranged in the photoconductive layer such that it produces a plurality of point defects.

Terahertz antenna and method for producing a terahertz antenna

A quantum cascade laser structure having a plurality of cascades each of which comprises a number of alternately arranged quantum wells and barriers of different thicknesses and heights, wherein at least one of the quantum wells and at least one of the barriers is under mechanical strain and the quantum wells and the barriers are coordinated such that the existing mechanical strains are largely compensated within one cascade, wherein each of the barriers comprise one or more barrier layers, wherein each cascade comprises a thinnest quantum well, a lowest barrier, a thickest quantum well, a highest barrier, and the highest barrier is followed by alternately arranged quantum wells and barriers.

Quantum cascade laser structure

A quantum well structure according to the invention includes a quantum well layer () arranged between two barrier layers (). It is distinguished in that at least one of the barrier layers () includes nanostructures () which compensate or modulate a lateral homogeneity of the barrier layer (), that exists without the nanostructures (), that is to say a homogeneity in the directions extending perpendicularly to the stacking direction of the layers in the quantum well structure.

Quantum well structure

A quantum cascade laser structure in accordance with the invention comprises a number of cascades (), each of which comprises a number of alternately arranged quantum wells (to) and barrier layers (to). The material of at least one quantum well (to) as well as the material of at least one barrier layer (to) is under mechanical strain, with the respective strain being either a tensile strain or a compression strain. The quantum wells (to) and barrier layers (to) are engineered in the quantum cascade laser structure in accordance with the invention so that existing strains are largely compensated within a cascade (). In the quantum cascade laser structure in accordance with the invention, each material of the quantum wells (to) has only one constituent material and the material of at least one barrier layer () has at least two constituent materials ().

Growing community of inventors

Berlin, Germany

Mykhaylo Semtsiv